INFLUENCE OF THE VARIATION OF THE CLIMATIC PARAMETERS IN THE MODELLING OF SWTA: STUDY OF CASE HYDROGRAPHIC BASIN OF THE RIVER TAPAJÓS

Abstract

ABSTRACT: Changes in the use and occupation of the soil have caused modifications in hydrological systems. Thus, prior knowledge on the effect of variations in the use of the soil and the dynamics of waters in the river basins is important to predict, mitigate and/or eliminate activities and interventions with negative impacts. In this context, hydrological models are important tools for these predictions. This work aimed at showing if the SWAT modeling is able of simulating satisfactorily the flows in the basin of Tapajós river, comparing the data obtained through the simulations with the flows observed during the period from 1999 to 2002. It also verified how different inputs of climatic parameters affect the simulations. As modeling inputs, three fluviometric points were used: Acará dos Tapajós, Fazenda Tratex and Jardim do Ouro; Pedology provided by the Brazilian Agricultural Research Corporation (EMBRAPA); use and occupation of the soil performed through the supervised classification of 32 Landsat images ( (January 2001 to December 2001); The digital elevation model (MDT) using Shuttle Radar Topography Mission (SRTM) images; Regarding the climatic parameters, two sources were used: National Institute of Meteorology (INMET) and Global Precipitation Climatology Project (GPCP). In the simulation with INMET climatic data, COE values were obtained (0.81, 0.86 and 0.79) and they were considered very good and higher compared with the results of the simulations with GPCP weather inputs. The work show, thus, that the model has a good correlation with the real data and represents the hydrological behavior of the basin of Tapajós river.KEYWORDS: Flow, Hydrological modelling, Variations in soil use.